This invention relates to a welding robot and more particularly to an improved apparatus and method for arc welding thin sheets of metal.
A variety of automatic welding devices have been proposed for arc welding, a most common type being the MAG welders that provide automatic gas shielded arc welding and which have welding torch which is moved along the seam to be welded by a robot with the speed of motion, diameter of weld rod, welding current and other factors being controlled in accordance with the thickness of the materials being welded. When butt welding, the two materials to be joined have their edges positioned in abutting relationship and the weld rod or wire is fed along the direction of the butted joint.
However, this type of apparatus presents certain problems in connection with welding thin sheets of material. If the edges to be jointed are not completely straight and in abutting relationship without any gaps, then the amount of welding heat can be too great for the thickness of the material and voids in the weld can occur. This is because the molten metal can fall through the gap between the edges of the material being welded. Although this can be avoided by using very sensitive welding techniques and also by assuring extreme accuracy in the edges being joined, such complicated systems and the provision of such high accuracies in forming the edges to be welded significantly increase the cost of the apparatus and reduces the efficiency of the welding technique.
It is, therefor, a principal object of this invention to provide an improved apparatus and method for welding thin sheets of material.
It is a further object of this invention to provide an improved method and apparatus for arc welding joining edges of thin sheets of material.